Fold-and-Form: Trenchless Rehabilitation of an 1,800m DN700 Raw Water Transmission Main
By delivering a green, high-speed, and high-performance solution, Anyue successfully secured the region's industrial water supply.
The Challenge: Aging Infrastructure & Critical Industrial Supply
Located in the industrial heart of Yunnan Province, this DN700 raw water transmission main serves as a vital artery, securing the daily production water supply for multiple major manufacturing facilities along its route.
Originally constructed in the 1970s, the pipeline had been in continuous service for nearly 50 years—far exceeding its design lifespan. Decades of operation had left the infrastructure severely deteriorated. The pipe interior suffered from heavy corrosion, severe tuberculation, scale buildup, and structural leakage.
Compounding the issue was a massive infestation of bio-fouling (shellfish attachment). Together, these factors severely restricted hydraulic capacity, compromised water quality, and triggered a high risk of catastrophic pipe bursts, threatening local economic stability.
Complex Site Conditions & Environmental Constraints
Conventional open-cut replacement was deemed impossible due to extreme logistical and environmental constraints:
Environmental Sensitivity: The alignment traverses a protected ecological park and runs directly adjacent to a major reservoir.
Urban Obstacles: The route crosses underneath a busy municipal highway and includes a challenging 200-meter river-crossing section.
Extreme Geometry: The existing utility network was densely congested, with certain access shafts featuring a steep vertical drop of up to 10 meters.
Traditional excavation would have decimated the local landscape, paralyzed urban traffic, and forced prolonged shutdowns for critical downstream factories.
The Solution: Fold-and-Form Thermoplastic Lining
To mitigate environmental impact, minimize traffic disruption, and maintain uninterrupted production for local enterprises, the project team deployed Anyue’s Fold-and-Form Thermoplastic Lining technology.
This trenchless method allowed for fully in-situ rehabilitation utilizing the existing pipe alignment, eliminating the need for extensive excavation. The factory-preformed thermoplastic liner was folded to easily navigate the tight access shafts and dense utility networks, inserted into the host pipe, and then expanded using steam and pressure to form a tight, structural, fit-for-purpose new pipe within the old one.
The Results: High Efficiency and Restored Performance
The trenchless approach delivered outstanding results, completing the first 700-meter section in just 7 days.
Zero Disruption: The project preserved the park’s vegetation, kept highway traffic flowing smoothly, and caused zero downtime for downstream industrial enterprises.
Hydraulic Upgrade: The newly lined pipe features an ultra-smooth, jointless interior surface, eliminating all friction losses caused by previous scale and biological fouling.
Structural Integrity: All structural leaks were permanently sealed, drastically mitigating burst risks and fully restoring the long-term structural reliability of the network.
By delivering a green, high-speed, and high-performance solution, Anyue successfully secured the region's industrial water supply, proving once again the immense value of advanced trenchless technology in extending the lifespan of critical infrastructure.
